Variable speed governor



Jan. 22, 1963 H. BETz 3,074,281

VARIABLE SPEED GOVERNOR Filed Nav. 17, 1959 2 Sheets-Sheet :1.

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/4/ VE #T0195 ,IMA/x 5E TZ Jan. 22, 1963 H. BETz VARIABLE SPEED GOVERNOR 2 Sheets-Sheet 2 Filed Nov. 17, 1959 United States Patent O Filed Nov. 17, 1959, Ser. No. 853,660 Claims priority, application Germany Nov. 22, 1958 6 Claims. (Cl. 73-531) This invention relates to a variable speed governor and, more particularly, to such a governor which is capable of governing speeds of rotation `over a ybroad range, i.e. an all-speed governor.

The conventional governors heretofore used in the art h-ave axially arranged springs or a spring arranged at the linkage to the m-ain drive. Such governors undesirably suffer from great internal friction, owing to ythe fact that the entire load of the governing spring force'employed is directly exerted on the governor pivots, wherelby the sensitiveness, the eciency and the life of the lgovernor .are reduced. The force, which must be exerted lon the operating lever for Variable speed change, is very great, especially in the upper part of the speed range, because it is necessary to counteract mechanically the force or" the governor springs in order to change the speed.

The known variable speed governors having radially arranged springs possess very small internal friction, because the centrifugal force of the fly weights is taken up directly by the springs. Under all operating conditions, the force required for varying speed is very small, as it is not necessary to counteract the full force of the springs. The variable speed control is effected by displacement of governor travel between full load and no load along the characteristic of the governor, .which is realized by means of an eccentric means. The disadvantage of these -governors is that the degree of admission is diminished at full load and at the lower part of the speed range. Therefore, the full capacity and the full torque of the engine cannot be utilized in all speeds.

it is an object of the invention to overcome the foregoing disadvantages and to provide a variable speed governor construct-ion which is capable of eiciently governing speeds over a very broad range and equally well with no load or full load.

Other and further objects of the invention will become apparent from a study of the within specification and accompanying drawings, in which FIG. 1 shows a side elevation, partially in section, of an embodiment of a centrifugal governor arrangement in accordance with the invention, partially broken away to indicate details of construction;

FIG. 2 shows a side elevation, partially in section, of another embodiment of a centrifugal governor arrangement in accordance with the invention;

FIG. 3 shows a partial vertical section, taken along line 3-=3 of FIG. l. This view is also identical to a similar partial section .taken along a corresponding line of FIG. 2;

FIG. 4 shows a speed diagram resulting from the inuence of the governor springs relative to the governors of FIG. 1 and FIG. 2, whereby the governor travel (s) is shown in the direction of the abscissa and the governor speed (n) in the direction of the ordinate;

FIG. 5 illustrates a side elevation, partially in section, of a further embodiment of .an arrangement in accord- Patented Jan. 22, 1963 ance with the invention, indicating a schematic linkage to the drive means regulator for a prime mover; and

FIG. 6 is a graphic representation of various spaced curves taken at several points along the variable speed range, using the arrangement shown in FIG. l whereby the governor ltravel (s) is shown in the direction of the abscissa and the governor speed (n) in the direction of the ordinate.

.In accordance with the present invention it has been found that a variable speed governor with radially arranged springs may be provided, whereby the capacity and the torque of the m-ain drive of an engine are constant or approximately constant over the whole speed range. In this way, the disadvantages of former variable speed governors with axially arranged springs or with springs arranged at the linkage, as well as variable speed governors with radially arranged springs hitherto known, are avoided while the advantages of these governors are utilized.

To this end, the outward axial movement of the con- Itrol rod of a governor having radially arranged springs is translated by a juxtaposed axially movable screw member into radial movement by means of a lever means connected to said screw member. The control rod may also be arranged for direct contact with lthe lever means.

In the former case, the juxtaposed screw is suitably seated in bushings for both axial and rotational movement in line with the axis of said control rod.

Rotation movement is caused by any gear means, such as a manual gear drive, cooperating with the bushing at the remote end of the juxtaposed screw, so that such remote bushing will rotate. An axially arranged groove within the remote bushing urges against a pin projection on the remote end of the juxtaposed screw, causing said screw to turn with the remote bushing. During axial movement of the juxtaposed screw, the pin projection merely travels back and forth along the axially arranged groove.

At the end of the screw, adjacent the governor control rod, a bushing ltherefor is provided which is pivotally carried by a lever means.

A pivot pin of the lever means passes through the adjacent end bushing and cooperates with threads provided on .the juxtaposed screw so that, upon rotational movement carried out at the remote bushing, the pivot pin of the lever means will guide the juxtaposed screw in axial direction. A compression spring or other suitable means normally urges the adjacent end bushing toward the control rod within the operation of the governor between full load and no load ranges at any of the adjustable variable speeds.

Upon axial outward movement of the control rod, the juxtaposed screw is urged in the direction of its remote end. This movement is taken up by the pivot pin of the lever means, causing corresponding movement of the lever means. The lever means is seated on a shaft so that back and forth movement of the lever is translated into limited rotational movement of the shaft. This shaft is suitably connected to the main drive means regulator of the prime mover, such as an engine or motor, so that outward movement of the control rod may suitably affect the regulation and disposition of the main drive means via the increment of rotational movement of the shaft.

In the more simplified case, where the control rod acts directly on the lever means, the lever means is eccentrically mounted about an eccentric pivot with the lever arm extending in the path of outward movement of the centrifugal governor control rod. An adjustable spring means may be provided to urge the lever arm in a direction toward the out-ward end of the control rod, so that the distance which the control rod must outwardly move before engaging the lever arm may be predetermined.

Upon such engagement, the lever means is pivoted a certain degree within the operation of the governor between full load and no load at any of the adjustable variable speeds, so as to cause a corresponding adjustment in the drive means regulator of the prime mover in connection with which the device is used.

Referring to the drawing, the centrifugal governor in accordance with FIG. 1 generally has a shaft 1 driven by the prime mover or motor (not shown). Two opposed fly Weights 2 are pivotally connected by pivots 3 to the governor shaft 1, so that the same will swing outwardly, due to centrifugal force upon rotation of the governor on the shaft. A pair of opposed threaded spindles 7 are connected to the governor shaft at right angles to its axis of rotation and extend through openings in the ily weights 2,. Surrounding the threaded spindles 7 are transverse compression springs 5, which oppose the outward movement of the fly weights 2. The outer ends of the springs are retained by the nuts 6, which are screwed on to the ends of the spindles 7. The inner ends of the springs press against spring supports 4 which are movably seated in the fly weights 2. The governor so far described basically has a construction as disclosed in U.S. Patent No. 2,807,455, dated September 24, 1957.

The movements of the fly weights 2 is transmitted to the control rod 9 by means of the transverse pivot 8, so that, as the fly weights 2 move outwardly, the control rod 9 will be moved axially in a direction extending forward from the governor, i.e. to the left as viewed in FIG. l. The control rod 9 moves the screw 1d in the forward direction of the governor axis. The screw 1t) is rotatably seated in bushing 11 and is moved axially in a cylindrical bore'with the bushing 11.

The bushing 11, as seen in FIG. 3`, is pivotally connected to the fork extensions of lever 12 by pins 13 and 14. The pin '14 has a greater length compared with the pin 13 and engages with its inner end the threaded portion of the screw 10. In this manner, the inner end of the pin 114 performs the simplified function of a nutY thread of the bushing 11.

The compression spring 15 presses against the bushing 11 so as to urge bushing 11 in opposite direction to the forward direction of rod 9. The lever 12 is firmly'xed tothe regulating lever shaft 16. It is limited in its travel b'y the adjustable screw 17 seated in casing 20. Lever shaft 16 is connected with the distributing mechanism of the prime mover by means of rods and levers not shown.

The bushing 18, provided ywith straight knurlings on its outer surface and seated for rotation, is turned via cooperating knurlings provided on the end surface of the bolt 21, which is seated in the governor casing 20. The spring '19 urges the bolt 21' in knurling contact with bushing 13. By turning the bolt 21, the slide key 22, which is fixed in the screw 1d, slides along the slide groove 23 provided within the bushing 18, whereby the screw moves in the direction of the governor axis due to the forward action of the threads.

Concerning the centrifugal governor according to FIG. 2, parts 1 to 9 generally correspond to parts 1 to 9 in FIG. 1. In FIG. 2, screw 10' is axially moved by the screw 25', which may be screwed inwardly and outwardly in cooperation with corresponding threads disposed on the inner surface of the governor casing 24. During this movement, the slide key 25', xed onto the screw 16', slides along the slide groove 27 provided within the screw 25.

Thescrew 10', which is axially moved by the governor rod 9', induces a turning of the regulating lever shaft 16 Iwithin a Small radial angle by means of the pin 114' (not shown) of bushing 11 and the lever 12. Lever 12 is limited in its travel by sere-w 17', and spring 15' urges bushing 11 to the right. The regulating lever shaft 16 is connected by a suitable linkage with the distributing mechanism for the fuel of the prime mover or motor in a way not shown. The screw 10' is turned by the screw 25'. Thus, the governor is induced to operate within another part of its travel.

With reference to the embodiments of FIGS. 1 and 2, as the case may be, during operation the screw 10 or 11) comes in contact with the control rod 9 or 9 against the action of the comparatively weak spring 15 or 15'. Spring 15 or 15 is not used for speed control. Its sole purpose is to keep the contact between control rod 9 or 9' and screw 10 or 19' within full load and no load range and, for example, within the distance (c) or (d) (see FIG. 4) according to the axial position of the screw 10 or 10'. Screw 1@ or 10 is adjustable by turning the bolt 21 or the screw 25. Without spring 15 or 15', no close arrangement or connection of the engine within the working range of the governor between full load and no load ranges would be possible;

lf the screw 10' or 10" is moved to the left (see FIGS.

1 and 2) a distance (a) (see FIG. 4), the governor has the speed n@ at full load. At no load, the governor moves the screw 10 or 1li" a distance 4(c), and no load speed increases up to the amount n2. In an upper speed range, the screw 10 or 10l is, for example, moved by the variable speed device by such an amount that the distance between control rod 9 or 9 and the screw 10 or 10', respectively, has achieved the distance (b) at full load and full load speed has increased up to n3. At no load, the governor moves the screw 1G or 10"' as far as the distance (d), and the no load speed achieves the amount n4.

The distributing mechanism to be used provides the prime mover approximately with the same fuel in the full load speeds n1 and n3 and also in the intermediate full load speeds, so that the capacity and the full torque of the prime mover can be utilized in all speeds. Therefore, the lever 12 does not change its angle at full load, i.e. at -the speeds nl, n3 of FIG. 4.

The difference of the angle at no load minus the angle at full load is variable. This difference depends upon:

(1) the governor travel between no load and full load, which is greater at high speeds than at low speeds,l and (2) the incline of the speed curve, which is greater at low speed than .at highspeed.

Therefore, the regulation (speed droop) is greater at low speeds than at high speeds.

The speed curves of FIG. 6 clarify this feature. For example, some of the speed curves achieved in practical tests at various positions of the screw 10 are shown for several points of the variable speed range of the arrangement shown in FIG. 1. The govern-or displaces the distributing mechanism or drive means regulator of the prime mover between full load and no load at all speeds within the lower part of the speed curves. The disposable governor travel must be sufficiently great at the highest speed for displacement between no load and full load.

The position of the distributing mechanism, which corresponds to the maximally admissible fuel, is adjustable by the stop screw 17 or 17. Furthermore, the position of the distributing mechanism relative to the governor can be changed by adjusting the stop screw 17 or 17.

Concerning the embodiment yof FIG. 5, a centrifugal governor of conventional construction is shown in which elements 1" to 9" generally correspond to elements 1 to 9 of FIG. 1. Upon axial outward movement of control rod 9", a juxtaposed lever 28 is urged in the direction of movement of the control rod. The axial movement of control rod 9" induces an angular or pivotal movement of the juxtaposed lever 28" which is fixedly secured to shaft 30"'.

y The pivotal movement of lever 2S is translated into limited rotational movement of shaft 30". Shaft 30"' is pivotally connected to the displaceable eccentric means 3-1. By turning the eccentric means 31, as for example by means of variable speed lever 32, shaft 30 is displaced in a direction approximately parallel to the governor axis and the distance (a) is changed (see FIG. 4). The lever 29 is fixedly secured to shaft 30 at one end and at the other end is connected by a suitable linkage with the distributing mechanism of the prime mover, in this case via displaceable pivot 33" with the throttle 36".

In the position shown in FIG. 5, the weak spring 34", mounted under slight tension between adjusting element 34a" and lever 28, urges the linkage against the adjustable stop 35 at full load position of the distributing mechanism, throttle 36, since there is no contact between control rod 9" and lever 23". This causes the throttle 36 to remain fully open, permitting maximal fuel utilization. In place of throttle 36, any other means, such as a fuel injector, may be used as for instance where the prime mover is a diesel engine. By turning the knob of element 34a, the tension of spring 34 may be suitably adjusted.

Upon axial movement of control rod 9" to the left, as viewed in FIG. 5, lever 28" is correspondingly displaced, causing rotation of shaft 30 and displacement of lever 29 due to the arrangement of eccentric 31". As lever 29 is displaced, a corresponding change in position of the throttle linkage away from stop 35" via displaceable pivot 33" is effected. The throttle thereby closes somewhat, which causes a reduction in the fuel supply to the prime mover. In this way, outward movement of the control rod, just as in Ithe embodiments shown in FIGS. l and 2, may suitably atect greater or smaller fuel dosages of the drive means regulator or fuel distributing mechanism via displacement of the particular shaft.

While the full load position of throttle 36" is not displaced via pivot 33, in consequence of displacement of shaft 30 by means of lever 32", the fuel load position of throttle 3'6 is influenced at part-load or no-load ranges induced by outward axial movement of control rod 9".

With reference to the embodiment of FIG. 5, during operation, lever 28" `comes in contact with control rod 9 within full load and no load positions against the action of the comparatively weak spring 34". If lever 28" is moved tothe left, as shown in FIG. 5, a distance (a) (see FIG. 4), the governor has the speed n1 at full load. At no load, the governor idisplaces lever 2B a distance (c), and no load speed increases to the amount n2. In an upper speed range, lever 28 may be, for example, displaced by the variable speed device by such an amount that the distance between control rod 9 and lever 28 is a distance (b) at full load, and full load speed is increased to n3. At no load the governor urges lever 28" a distance (d) and no load speed achieves the amount n4.

It will be understood that the thnottle linkage, shown in FIG. 5, may be suitably employed in connection with the variable speed regulator embodiments shown in FIGS. 1 and 2 in a similar manner as mentioned above. Thus, movement of shaft 16 or 16 may be translated by a linkage corresponding to that illustrated in FIG. 5, so as to control the drive means regulator, such as a throttle, fuel injector and the like, of the prime mover.

While the invention has been described in detail with reference to the specific embodiments, various changes and modications will become apparent to the skilled artisan, which fall within the spirit of the invention and scope of the appended claims. Thus, for example, the bushing 11 or 11 may engage with the screw 10 or 10', respectively, by a triangular thread instead of by a square thread as shown. The bushing 18 may be turned by means of bevel gear instead of straight knurling or by any other suitable means. Instead of the governor having 6 weights integral with bell cranks, as shown in the drawing, a governor provided with weights pivotally connected with bell cranks instead may be used.

Furthermore, in lieu of a governor having a static characteristic in high degree, as indicated in the speed diagram of FIG. 4, a two-step governor may be used with similarly excellent results, such as a maximum-minimum governor according to FIG. 3 of U.S. Patent 2,807,455, dated September 24, 1957, and FIGS. 1 and 2 according to British Patent 691,011; or a conventional variable speed governor, wherein several coaxially disposed springs opposing outward radial displacement of the iiy-weights of the governors are provided, which progressively come into play as the fly-weights move farther outwardly to achieve dynamic effect. Suitable governor constructions in this regard are illustrated in FIGS. 1 to 4 of British Patent 798,730, dated April 4, 1956, as well as in FIGS. 2 to 6 of French Patent 1,144,968, dated March 30, 1956.

What is claimed is:

1. A variable speed regulator for a prime mover governing speeds over a broad range with substantially constant capacity and torque of the prime mover within the no load and full-load ranges at all speeds over the broad range, comprising a centrifugal governor having flyweights outwardly moveable against spring force, a rst member actuated for axial movement by outward movement of the fly-weights of the governor, a second member positioned a predetermined distance from said first member for contact and movement thereby after outward movement of said fly-Weights a predetermined distance, resilient urging means opposing movement of said second member and maintaining said second member with respect to said rst member within the operational range of the governor between the no-load and full-load ranges at any adjustable variable speed of the governor, and means for transmitting movement of said second member to the drive means regulator of a prime mover in connection with which the device is used, said second member including lever means eccentrically pivotally mounted for pivotal movement about a displaceable axis of pivot in response to actuation by direct contact thereof with said rst member and said means for transmitting movement of said second member including linkage means interconnecting the eccentrically pivotally mounted lever means with said drive means regulator.

2. A variable speed regulator, according to claim l, including means for adjustably varying the predetermined distance said second member is positioned from said first member.

3. A variable speed regulator according to claim l, in which said centrifugal governor is a governor having at least two opposed outwardly pivotable fly-weights with radially positioned compression coil springs opposing the outward movement of said fly-weights.

4. A variable speed regulator according to claim l, wherein said resilient urging means are coil spring means provided for opposing the movement of said second member.

5. A Variable speed regulator according to claim 4, wherein the tension of said spring means is adjustable.

6. A variable speed regulator for a drive means, comprising a centrifugal governor having at least two radially arranged fly-weights outwardly movable against the force of springs with radially positioned compression coil springs opposing the outward movement of said ilyweights, said weights and springs being mounted for rotation with an axially extendable control rod, lever means juxtaposed with said control rod and eccentrically pivotally mounted for pivotal movement about a displaceable axis of pivot in response to actuation by direct contact thereof with said rod upon extension thereof, spring means opposing pivotal movement of said lever means and maintaining said lever means with respect to said control rod within the operational range of the governor between the no-load and full-load ranges and any adinstable, variable speed of the governor, and linkage means interconnecting the eccentrically pivotally mounted lever means with the drive means regulator o a prime mover in connection with which the device is used for transmitting the pivotal movement of said lever means to said drive means regulator.

References Cited in the le of this patent UNITED STATES PATENTS 818,718 Rumely Apr. 24, 1906 8 Kleinhan June 21, 1910 Noack Feb. 26, 1918 Reeves June 23, 1925 Goldberg Ian. 9, 1934 Stinson Sept. 22, 1953 Heinzmann Sept. 24, 1957 FOREIGN PATENTS Austria Feb. 10, 1959 France June 28, 1943 Italy Oct. 5, 1937 Italy Oct. 12, 1948 

1. A VARIABLE SPEED REGULATOR FOR A PRIME MOVER GOVERNING SPEEDS OVER A BROAD RANGE WITH SUBSTANTIALLY CONSTANT CAPACITY AND TORQUE OF THE PRIME MOVER WITHIN THE NO LOAD AND FULL-LOAD RANGES AT ALL SPEEDS OVER THE BROAD RANGE, COMPRISING A CENTRIFUGAL GOVERNOR HAVING FLYWEIGHTS OUTWARDLY MOVEABLE AGAINST SPRING FORCE, A FIRST MEMBER ACTUATED FOR AXIAL MOVEMENT BY OUTWARD MOVEMENT OF THE FLY-WEIGHTS OF THE GOVERNOR, A SECOND MEMBER POSITIONED A PREDETERMINED DISTANCE FROM SAID FIRST MEMBER FOR CONTACT AND MOVEMENT THEREBY AFTER OUTWARD MOVEMENT OF SAID FLY-WEIGHTS A PREDETERMINED DISTANCE, RESILIENT URGING MEANS OPPOSING MOVEMENT OF SAID SECOND MEMBER AND MAINTAINING SAID SECOND MEMBER WITH RESPECT TO SAID FIRST MEMBER WITHIN THE OPERATIONAL RANGE OF THE GOVERNOR BETWEEN THE NO-LOAD AND FULL-LOAD RANGES AT ANY ADJUSTABLE VARIABLE SPEED OF THE GOVERNOR, AND MEANS FOR TRANSMITTING MOVEMENT OF SAID SECOND MEMBER TO THE DRIVE MEANS REGULATOR OF A PRIME MOVER IN CONNECTION WITH WHICH THE DEVICE IS USED, SAID SECOND MEMBER INCLUDING LEVER MEANS ECCENTRICALLY PIVOTALLY MOUNTED FOR PIVOTAL MOVEMENT ABOUT A DISPLACEABLE AXIS OF PIVOT IN RESPONSE TO ACTUATION BY DIRECT CONTACT THEREOF WITH SAID FIRST MEMBER AND SAID MEANS FOR TRANSMITTING MOVEMENT OF SAID SECOND MEMBER INCLUDING LINKAGE MEANS INTERCONNECTING THE ECCENTRICALLY PIVOTALLY MOUNTED LEVER MEANS WITH SAID DRIVE MEANS REGULATOR. 